Field of the Invention
The present invention relates to an improved steam cracking process and system.
Description of Related Art
Steam cracking processes typically involve two main sections, the convection and pyrolysis section. The convection section of the steam pyrolysis cracking zone is used to heat the feed to the required reaction temperatures, often called the cross-over temperature, prior to entering the steam pyrolysis cracking unit, wherein the pyrolysis cracking reaction occurs. Steam pyrolysis cracking reactions typically convert a relatively heavy hydrocarbon feedstock, which may include of a wide range of hydrocarbon components, into lighter, and more desirable, hydrocarbons, including but not limited to ethylene, propylene, butadiene, mixed butenes and pyrolysis gasoline.
Steam pyrolysis is a useful process that utilizes Le Chatelier's principle to create a more favorable reaction environment. The reactions that occur within a steam cracking process have more molecules on the product side of the equilibrium. Such reactions proceed to the more desirable product side when the reaction is performed under low pressure, as is stated by Le Chatelier's principle. The reaction normally occurs at atmospheric pressure; and running the cracking reaction at conditions lower then atmospheric pressures can be very uneconomical. Other conventional processes utilize a catalyst instead of steam to lower the activation energy and therefore create more desired products. However, in steam pyrolysis processes the addition of a low molecular weight diluent, steam is utilized. The addition of the low molecular weight steam to the cracking reaction lowers the partial pressure of the reaction system and creates more favorable reaction conditions and therefore increased desired products are formed.
Therefore it is an object of the present invention to provide improved steam cracking process and systems.